Asphalt-containing projectable targets

ABSTRACT

A projectable target is made from a composition including a filler material and a binder for the filler material. The binder includes a mixture of asphalt and an asphalt modifier selected from polymers, waxes, asphaltites, and combinations thereof. In one embodiment, the asphalt modifier is a combination of polymer and wax, and the binder has a penetration from 0 dmm to 5 dmm at 25° C., a softening point from 80° C. to 175° C., and a viscosity from 1000 centipoise to 25,000 centipoise at 163° C. The composition is formed into the shape of the projectable target and hardened.

BACKGROUND OF THE INVENTION

This invention relates in general to projectable shooting targets of thetype commonly referred to as clay pigeons, and in particular tocompositions for use in manufacturing the targets.

In trap and skeet shooting, saucer-shaped targets are projected into theair by means of an ejection device past the location of the marksmen.The marksman's intention is to hit the flying target by a shot from ashotgun causing it to disintegrate. In addition to being able todisintegrate when hit by shotgun pellets, the targets are alsomanufactured to withstand transportation and handling, and to withstandthe strain they are subjected to when projected.

The properties of the shooting targets have typically been achieved byusing as starting material a mass consisting of pitch (coal tar or apetroleum pitch) and a filler material such as limestone powder or clay.In this mixture, the pitch acts as a binder for the filler material.

Certain pitches have undesirable properties and are unsuitable for claypigeons. Currently available supplies of acceptable pitch are becomingscarce and inadequate to meet demand. Prior efforts to find alternatematerials have produced unsatisfactory results, such as the pigeonsbeing too brittle, not acceptably frangible, too expensive, or otherwisefailing to meet consumer requirements.

Accordingly, there is a need for improved compositions for makingprojectable targets such as clay pigeons and alternative sources forbinders, which meet all functional requirements.

SUMMARY OF THE INVENTION

This invention relates to a projectable target made from a compositioncomprising a filler material and an improved binder for the fillermaterial. The binder comprises a mixture of asphalt and an asphaltmodifier selected from polymers, waxes, asphaltites, and combinationsthereof. In one embodiment, the asphalt modifier is a combination ofpolymer and wax, and the binder has a penetration within a range of from0 dmm to about 5 dmm at 25° C., a softening point within a range of fromabout 80° C. to about 175° C., and a viscosity within a range of fromabout 1000 centipoise to about 25,000 centipoise at 163° C. Thecomposition is formed into the shape of the projectable target andhardened.

In a particular example, the projectable target is made from acomposition comprising a filler material and a binder for the fillermaterial. The binder comprises a mixture of solvent extracted asphalt,hydrocarbon resin and wax. The solvent extracted asphalt is oxidized toa softening point within a range of from about 140° C. to about 180° C.,and the asphalt has a penetration of about 0 dmm at 25° C. Thehydrocarbon resin has a softening point within a range of from about120° C. to about 175° C.

Various aspects of the invention will become apparent to those skilledin the art from the following detailed description of the preferredembodiments along with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a perspective view of an example of a clay pigeon that can bemade from a composition according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The projectable targets of the invention are made from a compositioncomprising a filler material and a binder for the filler material asdescribed below.

Filler Material

The composition can include any suitable filler material or combinationsof different filler materials. Some examples include clay, calciumcarbonate (limestone), other ground rocks such as mica powder, asbestospowder or pumice powder, metal powders, in particular metal sulfates orsulfites, non-metallic sulfates or sulfites, metal oxides, talc,silicates such as sand, gypsum, fly ash, glass powder, magnesiumcarbonate, and titanium oxide. The filler may be in any suitable form,such as powdered or granulated.

The filler material can be included in any suitable amount in thecomposition. In one embodiment, the composition includes from about 20wt % to about 65 wt % filler material and from about 35 wt % to about 80wt % binder.

Binder

The binder for use in the composition is a mixture of asphalt and anasphalt modifier selected from polymers, waxes, asphaltites, andcombinations thereof. In one embodiment, the asphalt modifier is acombination of polymer and wax. In another embodiment, the asphaltmodifier is wax or asphaltite. In a further embodiment, the binder issubstantially free of pitch.

The binder has physical properties that in combination with the fillerallow the production of a projectable target having desirableproperties. For example, these properties may include the hardness(penetration), softening point and viscosity of the binder. In oneembodiment, the binder has physical properties including at least one ofa penetration within a range of from 0 dmm to about 5 dmm at 25° C., asoftening point within a range of from about 80° C. to about 175° C.,and a viscosity within a range of from about 1,000 centipoise to about25,000 centipoise at 163° C. In another embodiment, the penetration,viscosity and softening point of the binder are all within the definedranges.

In a particular example, the penetration of the binder is within a rangeof from 0 dmm to about 3 dmm at 25° C., or more particularly from 0 dmmto about 1 dmm at 25° C. The penetration can be measured by any suitablemethod, such as ASTM D-5.

In another example, the softening point of the binder is within a rangeof from about 90° C. to about 150° C., or more particularly from about100° C. to about 120° C. The softening point of the binder can bemeasured by any suitable method, such as the ring and ball method, ASTMD-36

In a further example, the viscosity of the binder is within a range offrom about 1,500 centipoise to about 10,000 centipoise at 163° C., ormore particularly from about 2,000 centipoise to about 5,000 centipoiseat 163° C. The viscosity of the binder can be measured by any suitablemethod, such as ASTM D4402.

Asphalt

The asphalt can be a naturally occurring asphalt or a manufacturedasphalt, for example, a petroleum-derived asphalt produced by apetroleum refining operation. Any type of asphalt can be used, such as astraight run asphalt, an oxidized asphalt, or an asphalt cement.

In some embodiments, the asphalt is a relatively hard asphalt, e.g., anasphalt having a penetration of not greater than about 15 dmm at 25° C.,not greater than about 5 dmm, not greater than about 2 dmm, or about 0dmm depending on the particular embodiment. The penetration can bemeasured by any suitable method, such as ASTM D-5. A hardened asphaltcan be obtained by oxidizing the asphalt and/or by the selection of thestarting asphalt.

The oxidizing process comprises blowing air, oxygen or an oxygen-inertgas mixture through the asphalt at an elevated temperature for a timesufficient to increase the softening point and thereby harden theasphalt to the desired properties. In some embodiments, the oxidizedasphalt has a softening point of at least about 100° C., at least about120° C., at least about 140° C., or at least about 150° C. depending onthe particular embodiment. The softening point of the asphalt can bemeasured by any suitable method, such as the ring and ball method, ASTMD-36.

In some embodiments, the asphalt is a solvent extracted asphalt. Solventextraction techniques are well-known in the art and typically employ theuse of a C3-C5 alkane, usually propane. These techniques are variouslyreferred to in the art as deasphalting or as producing a propanedeasphalted asphalt (PDA), a propane washed asphalt (PWA), or a propaneextracted asphalt (PEA). Typically such techniques involve treatingnormal crude oil and/or vacuum residue feedstock with such alkaneswhereby a treated asphalt is obtained in which the percentages ofasphaltenes and resins are increased. Any suitable solvent extractedasphalt can be used in the invention. Exemplary of the solvent extractedasphalts are PDA's sold by Alon USA Energy, Inc., Dallas, Tex., by CenexAsphalt, Laurel, Mont., and by Murphy Refining, Meraux, La.

Polymer

The asphalt modifier in the binder can include any suitable polymer, ora combination of different polymers. For example, a wide variety ofdifferent thermoplastic polymers known in the art may be suitable foruse in the binder.

In some embodiments, the polymer is a hydrocarbon resin. The hydrocarbonresins are low molecular weight thermoplastic polymers synthesized viathe thermal or catalytic polymerization of cracked petroleumdistillates, coal-tar fractions, terpenes, or pure olefinic monomers.The hydrocarbon resins include aliphatic, aromatic and alicyclic resins.

Some examples of hydrocarbon resins include the LX® series of petroleumhydrocarbon resins sold by Neville Chemical Co., Pittsburgh, Pa. Thesehydrocarbon resins are mixed aromatic/alicyclic in content. For example,LX®-1035 has a softening point of about 170° C., an iodine number (Wijs)of about 170, a molecular weight (GPC) of about 605, and a viscosity(Gardner) at 25° C. of about 35 (70% in toluene).

Other examples of hydrocarbon resins include the modified hydrocarbonresins sold by Neville Chemical Co. These are aromatic hydrocarbonresins. For example, AG-12-28 has a softening point of about 150° C., aniodine number (Wijs) of about 145, a molecular weight (GPC) of about710, and a viscosity (Gardner) at 25° C. of about 52 (70% in toluene).

In some embodiments, the polymer used in the binder has a relativelyhigh softening point. For example, the softening point may be greaterthan about 100° C., greater than about 120° C., or within a range offrom about 120° C. to about 180° C. depending on the particularembodiment.

Wax

The asphalt modifier in the binder can include any suitable wax, or acombination of different waxes. Some examples include synthetic waxes,petroleum waxes such as microcrystalline waxes and paraffin waxes, andpolyolefin waxes such as polyethylene waxes.

For example, Fischer-Tropsch waxes are examples of suitable syntheticwaxes. The Fischer-Tropsch waxes are polymethylenes made by polymerizingcarbon monoxide in the presence of hydrogen, using high pressure andunique catalysts. Any suitable Fischer-Tropsch wax can be used, forexample, a BARECO® PX-105 Polymer sold by Baker Petrolite Corp., SugarLand, Tex. This wax has a softening point of about 105° C., apenetration of about 1 dmm (25° C., a viscosity of about 110 SUS@ 99°C., and a white color.

Petroleum waxes consist of mixtures of paraffinic, isoparaffinic andnaphthenic hydrocarbons. The physical differences between various typesof petroleum wax are due to the relative extent of the three types ofhydrocarbons present and the molecular weight of the hydrocarbons.Microcrystalline waxes contain higher amounts of isoparaffinichydrocarbons and naphthenic hydrocarbons than do paraffin waxes. Typicalmicrocrystalline wax crystal structure is small and thin, making themmore flexible than paraffin wax. Any suitable microcrystalline wax canbe used, for example, any of the BARECO® microcrystalline waxes sold byBaker Petrolite Corp. Low melt brands of BARECO® Wax include BE SQUARE®,STARWAX®, VICTORY® AND ULTRAFLEX® Waxes. These waxes have softeningpoints within a range of about 66° C. to about 93° C., a penetration≧6dmm (25° C., 30-60% normal paraffins, and a dark brown to off whitecolor. A particular example is a BE SQUARE® 185, Amber Wax having asoftening point of about 91° C. and a penetration of about 10 dmm@ 25°C.

The wax can have any suitable physical properties. In some embodimentsthe wax has a softening point within a range of from about 65° C. toabout 120° C. and a penetration within a range of from about 1 dmm toabout 15 dmm@ 25° C.

The wax can be included in any suitable amount in the binder. When thebinder includes asphalt and wax, in one embodiment the binder comprisesfrom about 60 wt % to about 95 wt % asphalt and from about 5 wt % toabout 40 wt % wax. When the binder includes asphalt, polymer and wax, inone embodiment the binder comprises from about 50 wt % to about 90 wt %asphalt, from about 5 wt % to about 30 wt % polymer and from about 5 wt% to about 20 wt % wax.

Asphaltite

The asphalt modifier in the binder can include any suitable asphaltite,or a combination of different asphaltites. The asphaltites aregilsonite, grahamite and glance pitch. These are naturally occurringhydrocarbon substances characterized by a high softening point (above110° C.). They are mined much like other minerals and sold essentiallyin their native state. They are fully compatible with asphalt. In someembodiments of the invention, gilsonite is used as the asphalt modifier.Gilsonite is currently sold in the form of a dry bulk solid granularpowder.

The asphaltite can be included in any suitable amount in the binder. Inone embodiment, the binder comprises from about 60 wt % to about 95 wt %asphalt and from about 5 wt % to about 40 wt % asphaltite.

Other Additives

In addition to the above-described materials, the composition for makingthe projectable targets may also optionally include one or moreadditives. For example, such additives may include sulfur, surfactants,release agents, set-controlling agents, antioxidants, pigments,lubricants and/or fire retardants.

Projectable Target

The projectable target may be useful for trap or skeet shooting, forcompetition or sport shooting, or for any other type of activity using aprojectable target.

The projectable target can have any shape and size suitable for itsintended use. As known in the art, clay pigeons include various shapesand sizes, including standard clay pigeons, a slightly different set ofdimensions for “Olympic” targets, both of which are generallysaucer-shaped, and a “running rabbit” target which has much differentdimensions and shape (essentially a flat-disc). The projectable targetis usually shaped so that its trajectory is stable when it is propelled,and is manufactured to a specified size and weight.

FIG. 1 shows an example of a clay pigeon 10 that can be made from acomposition according to the invention. It is recognized that the claypigeon and other types of projectable targets can have other suitableshapes and sizes, and that the invention is not limited to anyparticular form.

After the projectable target has been formed and hardened, the outsideof the targets may optionally be coated with any suitable coating. Insome embodiments, the coating is a colored coating such as a paint,finish or stain. Any suitable type of paint can be used, such as anenamel or lacquer paint.

Properties of the Projectable Target

The projectable target is strong enough to avoid breaking apart when itis launched into the air and also during normal transportation andhandling. At the same time, the target has sufficient brittlenessenabling it to disintegrate when hit by shotgun pellets. The brittlenesscan be measured by any suitable method. For example, the target may havesufficient brittleness and dimensions such that when shot at with birdshot from a twelve gauge shotgun from a distance of 25 meters byshooters skilled enough to hit about 98% of the targets from thatdistance, less than about 10% of targets hit by at least one pellet willremain unbroken.

Method of Manufacture

The projectable target can be manufactured by any suitable method. Someexamples of manufacturing methods that may be used, depending on theparticular composition, include molding, casting or pressing. Claypigeons are often formed by mixing together the materials of thecomposition and then molding the mixture into the desired shape. Forexample, the materials may be mixed by using machines such as mixers,mixing rolls or kneaders. The materials may be mixed under heatedconditions to facilitate the mixing, for example by using a mixer havinga heating device. The mixed materials may then be molded using anysuitable molding method, such as injection molding or compressionmolding. The mixed materials may be powdered, granulated or pelletizedbefore it is fed into the molding machine. Further, the heating andblending step may be accomplished in the molding process by using aninjection molding machine having a premixing-preplasticizing device suchas an injection molding machine with a blend-feeder. After theprojectable targets have been formed and hardened, the outside of thetargets may be coated with any suitable coloring material.

EXAMPLES

A projectable target is made by molding a composition including a fillermaterial and a binder. The binder is a mixture of asphalt, hydrocarbonresin and wax. The asphalt is a solvent extracted asphalt which isoxidized to a softening point within a range of from about 140° C. toabout 180° C., and more particularly from about 140° C. to about 160° C.The asphalt has a penetration of about 0 dmm at 25° C. The hydrocarbonresin has a softening point within a range of from about 120° C. toabout 175° C. The hydrocarbon resin is included in an amount within arange of from about 5% to about 40% by weight of the binder, moreparticularly from about 10% to about 30%. The wax is included in anamount within a range of from about 1% to about 10% by weight of thebinder, more particularly about 5%.

A projectable target is made by molding a composition containing 45 wt %bentonite clay and 55 wt % binder. The binder contains 75 wt % PDAasphalt (from Alon) oxidized to a softening point of 149° C., 20 wt %hydrocarbon resin (LX-1035® from Neville), and 5 wt % Fischer-Tropschwax (BARECO® PX-105 from Baker Petrolite).

Another projectable target is made by molding compositions containing 45wt % bentonite clay and 55 wt % binder. The binder contains 90 wt % PDAasphalt and 10 wt % Fischer-Tropsch wax.

Another projectable targets is made by molding compositions containing45 wt % bentonite clay and 55 wt % binder. The binder contains 90 wt %PDA asphalt and 10 wt % gilsonite.

In accordance with the provisions of the patent statutes, the principleand mode of operation of this invention have been explained andillustrated in its preferred embodiments. However, it must be understoodthat this invention may be practiced otherwise than as specificallyexplained and illustrated without departing from its spirit or scope.

1. A projectable target made from a composition comprising a fillermaterial and a binder for the filler material, the binder comprising amixture of asphalt and an asphalt modifier selected from the groupconsisting of polymers, waxes, asphaltites, and combinations thereof,the composition being formed into the shape of the projectable targetand hardened.
 2. The projectable target defined in claim 1 wherein thebinder has physical properties including at least one of a penetrationwithin a range of from 0 dmm to about 5 dmm at 25° C., a softening pointwithin a range of from about 80° C. to about 175° C., and a viscositywithin a range of from about 1000 centipoise to about 25,000 centipoiseat 163° C.
 3. The projectable target defined in claim 2 wherein thepenetration, viscosity and softening point of the binder are all withinthe defined ranges.
 4. The projectable target defined in claim 1 whereinthe penetration of the binder is within a range of from about 0 dmm toabout 3 dmm at 25° C.
 5. The projectable target defined in claim 1wherein the softening point of the binder is within a range of fromabout 90° C. to about 150° C.
 6. The projectable target defined in claim1 wherein the viscosity of the binder is within a range of from about1,500 centipoise to about 10,000 centipoise at 163° C.
 7. Theprojectable target defined in claim 1 which has a brittleness enablingthe target to disintegrate when hit by shotgun pellets.
 8. Theprojectable target defined in claim 1 wherein the asphalt is a solventextracted asphalt.
 9. The projectable target defined in claim 1 whereinthe asphalt modifier comprises a combination of polymer and wax.
 10. Theprojectable target defined in claim 9 wherein the polymer is ahydrocarbon resin.
 11. The projectable target defined in claim 9 whereinthe binder comprises from about 50 wt % to about 90 wt % asphalt, fromabout 5 wt % to about 30 wt % polymer and from about 5 wt % to about 20wt % wax.
 12. The projectable target defined in claim 1 wherein theasphalt modifier comprises wax.
 13. The projectable target defined inclaim 12 wherein the wax has a softening point within a range of fromabout 50° C. to about 170° C.
 14. The projectable target defined inclaim 12 wherein the binder comprises from about 60 wt % to about 95 wt% asphalt and from about 5 wt % to about 40 wt % wax.
 15. Theprojectable target defined in claim 1 wherein the asphalt modifiercomprises asphaltite.
 16. The projectable target defined in claim 15wherein the binder comprises from about 60 wt % to about 95 wt % asphaltand from about 5 wt % to about 40 wt % asphaltite.
 17. A projectabletarget made from a composition comprising a filler material and a binderfor the filler material, the binder comprising a mixture of asphalt,polymer and wax, the binder having a penetration within a range of from0 dmm to about 5 dmm at 25° C., a softening point within a range of fromabout 80° C. to about 175° C., and a viscosity within a range of fromabout 1000 centipoise to about 25,000 centipoise at 163° C., thecomposition being formed into the shape of the projectable target andhardened.
 18. A projectable target made from a composition comprising afiller material and a binder for the filler material, the bindercomprising a mixture of: solvent extracted asphalt which is oxidized toa softening point within a range of from about 140° C. to about 180° C.,the asphalt having a penetration of about 0 dmm at 25° C.; hydrocarbonresin having a softening point within a range of from about 120° C. toabout 175° C.; and wax; the composition being formed into the shape ofthe projectable target and hardened.
 19. The projectable target definedin claim 18 wherein the hydrocarbon resin is included in an amountwithin a range of from about 5% to about 40% by weight of the binder.20. The projectable target defined in claim 18 wherein the wax isincluded in an amount within a range of from about 1% to about 10% byweight of the binder.